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explain_iconv_open(3) Library Functions Manual explain_iconv_open(3)
NAME
explain_iconv_open - explain iconv_open(3) errors
SYNOPSIS
#include <libexplain/iconv_open.h>
const char *explain_iconv_open(const char *tocode, const char *from-
code);
const char *explain_errno_iconv_open(int errnum, const char *tocode,
const char *fromcode);
void explain_message_iconv_open(char *message, int message_size, const
char *tocode, const char *fromcode);
void explain_message_errno_iconv_open(char *message, int message_size,
int errnum, const char *tocode, const char *fromcode);
DESCRIPTION
These functions may be used to obtain explanations for errors returned
by the iconv_open(3) system call.
explain_iconv_open
const char *explain_iconv_open(const char *tocode, const char *from-
code);
The explain_iconv_open function is used to obtain an explanation of an
error returned by the iconv_open(3) system call. The least the message
will contain is the value of strerror(errno), but usually it will do
much better, and indicate the underlying cause in more detail.
The errno global variable will be used to obtain the error value to be
decoded.
tocode The original tocode, exactly as passed to the iconv_open(3)
system call.
fromcode
The original fromcode, exactly as passed to the iconv_open(3)
system call.
Returns:
The message explaining the error. This message buffer is shared
by all libexplain functions which do not supply a buffer in
their argument list. This will be overwritten by the next call
to any libexplain function which shares this buffer, including
other threads.
Note: This function is not thread safe, because it shares a return buf-
fer across all threads, and many other functions in this library.
Example: This function is intended to be used in a fashion similar to
the following example:
iconv_t result = iconv_open(tocode, fromcode);
if (result < 0)
{
fprintf(stderr, "%s\n", explain_iconv_open(tocode, from-
code));
exit(EXIT_FAILURE);
}
The above code example is available pre-packaged as the ex-plain_iconv_open_or_die(3) function.
explain_errno_iconv_open
const char *explain_errno_iconv_open(int errnum, const char *tocode,
const char *fromcode);
The explain_errno_iconv_open function is used to obtain an explanation
of an error returned by the iconv_open(3) system call. The least the
message will contain is the value of strerror(errno), but usually it
will do much better, and indicate the underlying cause in more detail.
errnum The error value to be decoded, usually obtained from the errno
global variable just before this function is called. This is
necessary if you need to call any code between the system call
to be explained and this function, because many libc functions
will alter the value of errno.
tocode The original tocode, exactly as passed to the iconv_open(3)
system call.
fromcode
The original fromcode, exactly as passed to the iconv_open(3)
system call.
Returns:
The message explaining the error. This message buffer is shared
by all libexplain functions which do not supply a buffer in
their argument list. This will be overwritten by the next call
to any libexplain function which shares this buffer, including
other threads.
Note: This function is not thread safe, because it shares a return buf-
fer across all threads, and many other functions in this library.
Example: This function is intended to be used in a fashion similar to
the following example:
iconv_t result = iconv_open(tocode, fromcode);
if (result < 0)
{
int err = errno;
fprintf(stderr, "%s\n", explain_errno_iconv_open(err,
tocode, fromcode));
exit(EXIT_FAILURE);
}
The above code example is available pre-packaged as the ex-plain_iconv_open_or_die(3) function.
explain_message_iconv_open
void explain_message_iconv_open(char *message, int message_size, const
char *tocode, const char *fromcode);
The explain_message_iconv_open function is used to obtain an explana-
tion of an error returned by the iconv_open(3) system call. The least
the message will contain is the value of strerror(errno), but usually
it will do much better, and indicate the underlying cause in more de-
tail.
The errno global variable will be used to obtain the error value to be
decoded.
message The location in which to store the returned message. If a suit-
able message return buffer is supplied, this function is thread
safe.
message_size
The size in bytes of the location in which to store the re-
turned message.
tocode The original tocode, exactly as passed to the iconv_open(3)
system call.
fromcode
The original fromcode, exactly as passed to the iconv_open(3)
system call.
Example: This function is intended to be used in a fashion similar to
the following example:
iconv_t result = iconv_open(tocode, fromcode);
if (result < 0)
{
char message[3000];
explain_message_iconv_open(message, sizeof(message), tocode,
fromcode);
fprintf(stderr, "%s\n", message);
exit(EXIT_FAILURE);
}
The above code example is available pre-packaged as the ex-plain_iconv_open_or_die(3) function.
explain_message_errno_iconv_open
void explain_message_errno_iconv_open(char *message, int message_size,
int errnum, const char *tocode, const char *fromcode);
The explain_message_errno_iconv_open function is used to obtain an ex-
planation of an error returned by the iconv_open(3) system call. The
least the message will contain is the value of strerror(errno), but
usually it will do much better, and indicate the underlying cause in
more detail.
message The location in which to store the returned message. If a suit-
able message return buffer is supplied, this function is thread
safe.
message_size
The size in bytes of the location in which to store the re-
turned message.
errnum The error value to be decoded, usually obtained from the errno
global variable just before this function is called. This is
necessary if you need to call any code between the system call
to be explained and this function, because many libc functions
will alter the value of errno.
tocode The original tocode, exactly as passed to the iconv_open(3)
system call.
fromcode
The original fromcode, exactly as passed to the iconv_open(3)
system call.
Example: This function is intended to be used in a fashion similar to
the following example:
iconv_t result = iconv_open(tocode, fromcode);
if (result < 0)
{
int err = errno;
char message[3000];
explain_message_errno_iconv_open(message, sizeof(message),
err, tocode, fromcode);
fprintf(stderr, "%s\n", message);
exit(EXIT_FAILURE);
}
The above code example is available pre-packaged as the ex-plain_iconv_open_or_die(3) function.
SEE ALSOiconv_open(3)
allocate descriptor for character set conversion
explain_iconv_open_or_die(3)
allocate descriptor for character set conversion and report er-
rors
COPYRIGHT
libexplain version 1.3
Copyright (C) 2013 Peter Miller
explain_iconv_open(3)